Differences between Time to first Impression and Document Interactive
Hello forum,
I just approaching at User Experience performance monitoring and I've some doubts about metrics and their meaning. In particular I would exploring the differences (if there are) between "Time to first Impression" and "Document Interactive".
According to the Navigation Timing API the "Document Interactive" metric is measured when the domInteractive event occurs. Instead for the "Time to first Impression" I've some difficulties to map it on the API event.
Regards,
Luigi
Hi Luigi
Can you tell me for which feature in Dynatrace you want this answered? We capture Browser specific metrics both in Dynatrace when we do User Experience Management using our JavaScript Agent as well as Browser Diagnostics using our Browser Plugin. We also capture these timings with our Synthetic offering where we monitor availabilty and performance from different locations in the world. Just trying to figure out which product you are using as posted this question in the general Community Forum
Thanks
Hi Andreas,
I thinking about User Experience Management with JavaScript Agent. I would know if the agent is able to collect this kind of information and then eventually the differences between the two metrics. Even if there is a link with the Navigation Timing events.
However the definition and the measurement of the two metrics are not unique, indipendently from the tool?
Regards
Hi Luigi,
The "Time to first impression" is a metric that cannot be measured with the JavaScript agent and is not a W3C timing related metric. It is a measure that is only provided by the browser diagnostic agent (browser plugin) and it also not an official standard metric. It is a metric invented years ago by us due to a lack of other metrics.
The Document Interactive timing is a metric defined by the W3C standard. For details please take a look at W3C Navigation Timing Metrics in the documentation.
Klaus
Hi Klaus,
your explanation clarified the main doubt about Time to First Impression (TTFI), that is there isn't a direct link between the metric and the event defined by Navigation Timing.
However I think I'm missing the last bit of this discussion: isn't there any link between TTFI and Document Interactive? The first one represents the elapsed time taken by the browser to draw something, the second one is the elapsed time taken by the DOM to become interactive (i.e able to interact with the javascript).
Could work the definition I've provided?
Thank you for your support.
Luigi
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